Selective Enrichment and Direct Determination of Trace Drug by Solid-phase Extraction
Zhou Jie, Han Hongyan, He Xiwen , Shi Huiming (Department of Chemistry, Nanism. University, Tianjin, 300071)
A molecular template polymer (PIMP) capable of molecular recognition of trimethoprim (IMP), an antibiotic drug, was used in solid-phase extraction in order to selectively enrich IMP from a dilute solution. At a physiological concentration (40 nmol/L), an enrichment factor of 35. 7 was obtained. Whereas the non-template polymer (PO) with the same composition as PIMP had no enrichment ability to IMP. The high selectivity of PIMP allowed IMP to be detected directly in the desorption step, thus eliminating the need for a successive chromatographic analysis. Based on this, a new approach to enrichment and detennination of TMP was proposed. This simple and reliable method has been used to the direct detennination of TMP which was present in low concentration in urine sample. The recovery was up to 91.7%, and the satisfactory results were obtained.